5 papers
Nilpotent cohomological Hall algebras of surfaces
Duiliu-Emanuel Diaconescu, Mauro Porta, Francesco Sala +2
This paper develops a framework for systematically studying cohomological "Hecke operators" associated with modifications of coherent sheaves on a smooth surface along a fixed…
Kleinian orbifolds, Cohomological Hall Algebras, and Yangians
Francesco Sala, Olivier Schiffmann, Parth Shimpi
We establish, for each orbifold crepantly resolving a Kleinian singularity, the existence of the cohomological Hall algebra (COHA) of coherent sheaves supported on the exceptional…
Cohomological Hall algebras, their categorification, and their representations via torsion pairs
Duiliu-Emanuel Diaconescu, Mauro Porta, Francesco Sala
In this paper we provide a systematic way of producing representations of cohomological, K-theoretical and categorified Hall algebras, and study the output of our construction in s…
Flops and Hilbert schemes of space curve singularities
Duiliu-Emanuel Diaconescu, Mauro Porta, Francesco Sala +1
Using pagoda flop transitions between smooth projective threefolds, a relation is derived between the Euler numbers of moduli spaces of stable pairs which are scheme-theoretically…
Shuffle algebras for quivers as quantum groups
Andrei Neguţ, Francesco Sala, Olivier Schiffmann
We define a quantum loop group associated to an arbitrary quiver and maximal set of deformation parameters, with generators indexed by $I \times \mathbb{…